In a draft supplementary planning document (SPD) named Preventing Wasted Housing Supply (17-page / 373 KB PDF) the Council has proposed to require owners of new residential developments in the borough to enter into section 106 agreements to ensure that individual homes are used and occupied as dwelling houses.

The SPD said that, while only 5% of properties in the borough were listed as having "no usual resident" in the 2011 Census, a Council investigation had found that 30% of residential units completed in the borough in the last six years had nobody on the electoral register. For certain new developments, the Council's research found as many as 71% of market homes had nobody registered to vote.

The document proposed that freehold and head lease owners of individual homes would be required to include an obligation in leases and sub leases to ensure that the homes were occupied for at least 14 days in any three-month period. The owners would be required to provide the Council with "reasonable evidence of compliance with this obligation" and owners and developers would be required to ensure that prospective purchasers were aware of the requirement, the SPD said.

The policy was proposed to apply only to developments of 20 or more homes, but the Council said that the 20-unit threshold would remain under review. The Council proposed to enforce compliance with the terms of the section 106 agreements by using High Court injunctions. It said that persistent breaking of an injunction "could lead to a fine, prison and even seizure of the empty property".

The SPD said: "Given the acute need for housing delivery in Islington, along with the borough's constrained land capacity, the Council considers that the planning obligation contained in this SPD is necessary, reasonable and justified."

The Council's executive member for housing and development, councillor James Murray, said in a statement: "In Islington, as across London, there is a desperate shortage of housing. It's wrong when new homes sit there empty purely as investments, when Londoners are desperately trying to find somewhere to live."

"Our new proposals would make sure that all new homes in Islington are occupied – we want to send a message that 'buy-to-leave' is unacceptable," said Murray.